This invention relates to a power-generating control apparatus for a vehicle which enables a second power supply to absorb slowdown energy and permits revived driving efficiency for an electric power generator or electric motor during vehicle slowdown.
In a hybrid vehicle, an engine driven by combustion of fuel connects directly to an electric motor (called xe2x80x9cmotorxe2x80x9d hereinafter) which drives by electric energy and has a power-generating function.
The hybrid vehicle includes an engine control means for controlling a running state of the engine and a motor control means for controlling an operating state of the motor. Because the engine control means and the motor control means detect respective operating states of the engine and the motor when the vehicle is traveling, and the respective operating states of the engine and the motor are controlled in association with one another, such control system attains a high level of required performance (such as fuel efficiency, lower values of detrimental components in exhaust gases, and power performance).
In this case, a battery that supplies driving electric power to a motor and that is charged by generated electric power of the motor is established. The battery is administered for controlling driving power-generation/driving prohibition of the motor on the basis of a remaining quantity of energy in the battery.
Moreover, there is a hybrid vehicle which has an automatic start-up/stop control means to improve fuel efficiency or reduce effluent gas, by stopping an engine forcibly when stopping in an idling state.
One such example of a power-generating control apparatus of a vehicle is disclosed in published Japanese Application Laid-Open No. 11-257120. In an engine automatic stop/start-up control apparatus indicated in this disclosure, the capacitor which is used for driving a starter motor and charging a 12V supporting battery is charged by generated electric power that a motor driven by an engine generates. In an electronically controlled unit, based on a remaining residual capacity of a capacitor that is detected by a capacitor residual capacity sensor and consumed electric power that is detected by a 12V-based consumed electric power sensor, a determination is made as to whether an engine can restart by operating a starter motor by electric power of the capacitor, even if the engine is stopped. When electric power of the capacitor remains sufficient, the engine is stopped. As a result, fuel consumption is reduced. When electric power of the capacitor is not sufficient, the engine is not stopped, but is maintained in an idle driving state. Then, when the engine already is stopped, the engine is started up by operating a starter motor. Thus, by extending stop time of the engine of the vehicle as long as possible, the system reduces fuel consumption, and ensures performance of restart.
Incidentally, in a traditional vehicle, system maintenance of fuel injection and consumption of electricity by lights, a blower and windshield wipers are supplied by generated electric power of an alternator. Further, charging of a battery is performed simultaneously.
However, because most of the above-mentioned examples provide loading of an engine, fuel consumption is accompanied. Accordingly, there is inconvenience to be disadvantageous economically.
And, because it is the situation that charge (say xe2x80x9crevivalxe2x80x9d) at slowdown in which fuel does not need is not utilized positively, the improvement is expected.
In order to obviate or minimize the above inconvenience, a power-generating control apparatus, for a vehicle having an engine and a power-generator operated by the engine or electric motor, includes: a slowdown detecting means to detect a slowdown state of the vehicle, a main battery for the vehicle, and a sub-battery. The control apparatus includes a switch-over means which switches over at least either of the main battery and the sub-battery to the power-generator or motor, which in a slowdown state, in response to a detected signal from the slowdown detecting means, switches over to couple the power-generator or the motor and the sub-battery. In engine stop, the switch-over device switches over to the sub-battery as a power supply of operation load.
Accordingly, at slowdown, the sub-battery can be sufficiently charged to be used as a power supply for load operation, such as a control system of the engine and motor, a lamp and an air conditioning apparatus. Further, electric power of the main battery used at start-up is maintained.
Moreover, the present invention provides a power-generating control apparatus for a vehicle which disposes an engine and a power-generator operated by the engine or electric motor, comprising: a slowdown detecting means to detect a slowdown state of a vehicle; a first power supply as a main battery for the vehicle and a second power supply as a sub-battery; and a switch-over means which switches over at least either of the main battery and sub-battery to the power-generator or motor, which in slowdown state, in response to a detected signal from the slowdown detecting means, switches over to couple the power-generator or the motor and sub-battery. Moreover, when capacity of the sub-battery is larger than a predetermined value, the switch-over means switches to link the sub-battery to a power supply line. Accordingly, when the sub-battery is fully charged, it can always assist as a supporting power supply for the main battery. Further, this system can prevent an electric discharge and deterioration of a first power supply, and can contribute to stabilization of a vehicle system and improvement thereof.
By this invention, at slowdown, the sub-battery can be charged sufficiently to be used as a power supply for operation load, such as a control system for the engine and motor, a lamp and an air conditioning apparatus. Further, electric power of the main battery used at start-up is maintained. As a result, a quantity of charge needed for the main battery is decreased, and power-generating load by the power-generator or motor is reduced. Accordingly, this system can contribute to reduction of fuel usage. Moreover, because the sub-battery can absorb slowdown energy, driving efficiency of the motor at slowdown becomes excellent.